Stator assembly

ABSTRACT

A stator assembly ( 20 ) has a plurality of splayed stator poles ( 31 - 36 ). A first winding coil ( 51 ) is arranged on the first stator pole ( 31 ) between a first current rail ( 38 ) and the second current rail ( 40 ), the second winding coil ( 52 ) is arranged on the second stator pole ( 32 ) between the second current rail ( 40 ) rails and the third current rail ( 42 ), the third winding coil ( 53 ) is arranged on the third stator pole ( 33 ) between the third current rail ( 42 ) and the first current rail ( 38 ), the fourth winding coil ( 54 ) is arranged on the fourth stator pole ( 34 ) between the first current rail ( 38 ) and the second current rail ( 40 ), the fifth winding coil ( 55 ) is arranged on the fifth stator pole ( 35 ) between the second current rail ( 40 ) and the third current rail ( 42 ), and the sixth winding coil ( 56 ) is arranged on the sixth stator pole ( 36 ) between the third current rail ( 42 ) and the first current rail ( 38 ).

This application is a § 371 of PCT/EP02/13821, filed Dec. 6, 2002,claiming priority from DE 202 02 873.8, filed Jan. 22, 2002, the entiredisclosure of which is incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a stator assembly, in particular for anelectronically commutated motor.

BACKGROUND

In order to operate an electronically commutated motor with a lowoperating voltage, e.g. the battery voltage of a vehicle, at highrotation speed and with good efficiency, e.g. at 10,000 RPM or more, theresistance and inductance of the windings must be very low, and thismeans that a winding coil should have relatively few turns made of athick wire, so that the stator slots can be well filled with copperwire.

If stators are automatically wound using so-called “needle windingmachines,” it is in many cases not possible to vary the wire gauge of awinding coil, so that one winds multiple wires in parallel.

If one attempts to solve the problem by connecting identical windings inparallel, this results, for a three-phase motor, in four wires, whichmust be coupled to a terminal (U, V, W) of the stator winding. Thusarises the necessity for time-consuming, expensive manual work.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a new statorassembly.

In accordance with the invention, this object is achieved by the subjectmatter of claim 1. Through the invention, one achieves that, duringwinding, the connection between adjacent winding coils need not beinterrupted; rather, these coils can remain connected via wire contactterminals. These wire contact terminals are, preferably during thewinding process, so electrically secured to an associated current rail,that these current rails can serve as a terminal for the supply ofelectrical current to the stator winding. It is very advantageous thatthis enables automatic manufacture of the stator winding, since oftenthe electrical connection with the current rails can also be automatedand since the winding wire no longer need be interrupted during winding,but rather if necessary can be continuously wound from the first windingcoil through to the last winding coil.

The current rails, and possibly also the wire contact terminals betweenthe winding coil can be contained, e.g. at a front face of the statorarrangement, in one or more correspondingly formed insulating parts, sothat contact between wires of different winding phases and of differentwinding coils is reliably avoided. Short circuits in the region of thewinding are made impossible, which assures high electrical safety, astate which is absolutely necessary, e.g. on ships, planes or landvehicles.

Due to the subject matter of claim 1, one thus achieves, in a verysimple manner, a stator assembly whose three-phase winding is connectedin a delta configuration, each phase comprising a plurality of parallelconnected winding coils, continuously would and connected to each otherat their ends by current rails. These current rails can also serve totransport electrical energy to or from the stator assembly. These railsare preferably provided with solder terminals or the like, which projectdirectly into an adjacent circuit board and there are connected to theend stage transistors of the electronically commutated motor. Even inthe case of high currents, it is possibly to sharply reduce losses inthe conducting leads, i.e. the invention makes high operating efficiencypossible.

Further details and advantageous refinements of the invention areapparent from the preferred embodiment described below and shown in thedrawings, which is not to be construed as any limitation of theinvention.

BRIEF FIGURE DESCRIPTION

FIG. 1: a schematic drawing of a winding arrangement according to apreferred embodiment of the invention;

FIG. 2: a section, looking along line II-II of FIG. 1;

FIG. 3: an enlarged detail of FIG. 2, for better illustration ofinsulator 44 with copper rails 38 and 42; and

FIG. 4: a circuit schematic for explanation of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows the usual schematic illustration of a stator assembly 20,here representing the stator of an electronically commutated internalrotor motor, whose four-pole permanent-magnet rotor 22 and whose shaft23 are schematically indicated. The invention is also suitable for use,e.g. in similar fashion, for a linear motor.

Stator assembly 20 has a standard lamination stack 26 wherein, within anangular range of 360°, six splayed poles 31, 32, 33, 34, 35 & 36 areprovided. On an outer face of stator assembly 20, there are a U-copperrail 38 with a connection terminal 39, a V-copper rail 40 with aconnection terminal 41, and a W-copper rail 42 with a connectionterminal 43. These rails each extend through an arc of about 180° andare arranged on the facade of stator assembly 20 in an insulatingannular part 44, shown in section in FIG. 2 and 3. This part is,according to FIGS. 2 & 3, arranged between the winding head of aschematically indicated stator winding 45 and the housing 46 of themotor. Since copper rails 38, 40, 42 each extend over 180°, at eachpoint of the circumference, only two overlapping copper rails arepresent, e.g. at the 12 o'clock position of FIG. 1, the rails 40 (outer)and 38 (inner). Each rail extends over about 90° radially outside andover about 90° radially inside, as shown in FIG. 1.

Describing in terms of a clock face, the U-copper rail 38 extendsapproximately from 6 o'clock to 12 o'clock. The V-copper rail 40 extendsfrom about 10 o'clock to 16 o'clock (4 PM). The W-copper rail 42 extendsfrom about 2 o'clock to 8 o'clock. These copper rails are insulated fromeach other by the insulator 44. Their contact terminals 39, 41, 43 servefor electrical connection with a circuit board 47 (FIGS. 2 & 3), onwhich are arranged the power transistors 48 for control of the currentsin the stator winding 45. In this manner, one achieves extremely shortsupply leads and thus low power losses in these leads. An end shield orbell is designated 49 and 50 designates a bearing for shaft 23.

On the stator poles are identical winding coils whose consistent windingdirection is shown in FIG. 1. On the first stator pole 31 is a firstwinding coil 51. One begins with winding of this coil, after thestarting end 50 of winding wire 44 is fastened at a point A (6 o'clock)to the U-rail 38. Point A is shown in FIGS. 2 & 3 in section and onerecognizes that, at this position, the contact terminal A of copper rail38 extends out of insulator 44 and this terminal A is connected to wireend 50, e.g. by welding. The subsequently described terminals B throughF are carried out in the same manner.

Copper rail 42, at the point of terminal A, is completely surrounded byinsulator 44, so that a short circuit between rails 38 and 42 is notpossible. The same is true, analogously, for the other rails; these are,in intervals between terminals, completely surrounded by insulator 44,and at the connecting points, only the terminal of a rail projects outof the insulator 44.

Appendant to coil 51, one winds the second winding coil 52 onto thesecond stator pole 32, then the third winding coil 53 onto the thirdstator pole 33, then the fourth winding coil 54 onto the fourth statorpole 34, then the fifth winding coil 55 onto the fifth stator pole 35and, finally, the sixth winding coil 56 onto the sixth stator pole 36.

There is thus created, between coils 51 and 52, a first wire loop 61which is electrically and mechanically connected at a point B (4o'clock) to the V-rail 40, preferably without interrupting the windingwire 44.

Between coils 52 and 53, there is created a second wire loop 62 which isconnected at a point C (2 o'clock) to the W-rail 42.

Between coils 53 and 54, there is created a third wire loop 63 which isconnected at a point D (12 o'clock) to the U-rail 38 and thus connectsthe points A and D electrically to each other.

Between coils 54 and 55, there is created a fourth wire loop 64 which isconnected at a point E (10 o'clock) to the V-rail 40 and thus connectsthe points B and E electrically to each other.

Between coils 55 and 56, there is created a fifth wire loop 65 which isconnected at a point F (8 o'clock) to the W-rail 42 and thus connectsthe points C and F electrically to each other.

The free end of coil 56 is designated 66 and is connected at point A tothe U-rail 38 and the wire start 50. This terminates the winding.

FIG. 4 shows that a delta winding configuration is formed having, ineach phase, two winding coils connected in parallel, namely in phase 70,between contacts U and V, the coils 51 & 54, in phase 72, betweencontacts V and W, the coils 52 and 55, and in phase 74, between contactsW and U, the coils 53 and 56. From FIG. 4, it is also clearly evidentthat U-rail 38 connects contacts A and D, V-rail 40 connects thecontacts B and E, and W-rail 42 connects the contacts C and F. One alsorecognizes in FIG. 4 the layout of wire loops 61 through 65, and of thewire start 50 and end 66.

Naturally, within the scope of the invention, many variations andmodifications are possible. For example, the winding arrangement of theinvention is adaptable in similar fashion for an external rotor motor,or for a linear motor. In connecting to six stator poles, the statorarrangement can be repeated arbitrarily often, a task which isstraight-forward to those of ordinary skill in the electrical machineryarts.

1. A stator assembly having a plurality of stator poles (31-36), said plurality being divisible by six, a first (31), a second (32), a third (33), a fourth (34), a fifth (35) and a sixth (36) of said stator poles being arranged successively within a predetermined angular range; three winding phases (70, 72, 74) connected in a delta configuration; three respective current rails (U, V, W, 38, 40, 42) associated with respective ones of said winding phases for their connection; wherein a first winding coil (51) is arranged on said first stator pole (31) and electrically connected between a first one (38) of said current rails and a second one (40) of said current rails; a second winding coil (52) is arranged on said second stator pole (32) and electrically connected between said second current rail (40) of said current rails and a third one (42) of said current rails; a third winding coil (53) is arranged on said third stator pole (33) and electrically connected between said third current rail (42) and said first current rail (38); a fourth winding coil (54) is arranged on said fourth stator pole (34) and electrically connected between said first current rail (38) and said second current rail (40); a fifth winding coil (55) is arranged on said fifth stator pole (35) and electrically connected between said second current rail (40) and said third current rail (42); and a sixth winding coil (56) is arranged on said sixth stator pole (36) and electrically connected between said third current rail (42) and said first current rail (38); wherein at least two successive winding coils (51, 52) are continuously wound and at their interface (61) are electrically connected to an associated current rail (40) without interrupting their winding wire (44).
 2. The stator assembly of claim 1, wherein the winding coils of the first through sixth winding coils are continuously wound and are electrically connected at their respective interfaces (61-65) to respective current rails, without interrupting their winding wires.
 3. The stator assembly according to claim 1, wherein at least one of said current rails (38, 40, 42) is configured to electrically interconnect a plurality of interface points (61, 64), said interface points being separated by three intervening stator poles.
 4. The stator assembly according to claim 1, wherein there are three stator poles per pole pair of the rotor (22).
 5. The stator assembly according to claim 4, wherein a terminal (U, V, W) is electrically connected with a circuit board (47) which is arranged adjacent an outer face of the stator assembly (20).
 6. The stator assembly according to claim 5, further comprising at least one power semiconductor (48) provided on said circuit board (47) for controlling current in a phase (70, 72, 74) of the stator winding phases (45).
 7. The stator assembly according to claim 1, wherein said current rails (38, 40, 42) are embedded within an insulating body (44) and are, except for terminals (A-F, U, V, W) of said rails, substantially completely enclosed by said body.
 8. The stator assembly according to claim 7, wherein, at a terminating point (A-F, U, V, W), a respective terminal (A, 43) projects out of the insulating body (44).
 9. An electronically commutated DC motor having a stator assembly with a plurality of stator poles (31-36), said plurality being divisible by six, a first (31), a second (32), a third (33), a fourth (34), a fifth (35) and a sixth (36) of said stator poles being arranged successively within a predetermined angular range; three winding phases (70, 72, 74) connected in a delta configuration; three respective current rails (U, V, W, 38, 40, 42) associated with respective ones of said winding phases for their connection wherein a first winding coil (51) is arranged on said first stator pole (31) and electrically connected between a first one (38) of said current rails and a second one (40) of said current rails; a second winding coil (52) is arranged on said second stator pole (32) and electrically connected between said second current rail (40) of said current rails and a third one (42) of said current rails; a third winding coil (53) is arranged on said third stator pole (33) and electrically connected between said third current rail (42) and said first current rail (38); a fourth winding coil (54) is arranged on said fourth stator pole (34) and electrically connected between said first current rail (38) and said second current rail (40); a fifth winding coil (55) is arranged on said fifth stator pole (35) and electrically connected between said second current rail (40) and said third current rail (42); and a sixth winding coil (56) is arranged on said sixth stator pole (36) and electrically connected between said third current rail (42) and said first current rail (38); wherein at least two successive winding coils (51, 52) are continuously wound and at their interface (61) are electrically connected to an associated current rail (40) without interrupting their winding wire (44); and a permanent magnet rotor (22), wherein said stator assembly (20) has three stator poles for each pole pair of said rotor (22). 